A machine tool comprising a tool magazine storing tools and a tool changer capable of automatically exchanging a tool is known in general. The spindle of such a machine tool has a structure capable of automatically attaching/detaching a tool so that the tool changer can automatically exchange the tool mounted on the spindle.
In order to exchange the tool mounted on the spindle of the machine tool, it is necessary to release the tool from the spindle of the machine tool through a tool attaching/detaching device. Japanese Patent Laying-Open No. 6-63806 describes an exemplary tool attaching/detaching device.    Patent Document 1: Japanese Patent Laying-Open No. 6-63806